Power transmission mechanism



NOV. 23, 194:3.` R, R, R0HKAR- 2,334,958 I l POWER TRANSMISSION MECHANISM Filed June 1o, 1942 2 sheets-sheet 1 NOV. 23, 1943. R, ROHKAR 2,334,958

POWER TRANSMISSION MECHANISM I y Filed June l0, 1942 2 sheets-'Sheet 2 mil I my will l l f?" pm@ iatenieri Non. 23, 1943 j 2,334,958 o POWER TRANSMISSION MECHANISM Raymond R. Rohkar,

Downers Grove, Ill.,l asm signor-to 'international Harvester Company, a corporation of New Jersey f o Application June 10, 1942, Serial 120.2446346 11 Claims.

This invention relates to a power transmis#` sion mechanism and more particularly to a change-speed transmission foral motor vehicle.

The present invention contemplates and has for its principal object the provision of a changespeed transmission incorporating mechanism for the establishment of a large number of speed ratios in both forward and reverse, together with a poweroutput shaft or power take-o shaft which may be operated independently of the operation of the change-Speed gearing or component parts thereof. o

An important object of the invention is to provide an improved power transmission providing for the obtaining of a plurality of speed ratlos in either forward. or reverse, there being preferably obtainable as many reverse Speeds as there are forward speeds.

Another important object is the provision of driving means for a power take-ofi shaftwhich may be operated independently of the direction of rotation of the main power output shaft of the transmission. l

Another object is the provision of a transmission having a hollow countershaft which mayV be rotated in either direction to drive the trans- ,v

mission through a multiplicity of speed ratios in either forward or reverse and to combine Y therewith an independently driven power takeoff shaft extending through the hollow countershaft.

' Another object is to provide a compact power transmission mechanism with a minimum of Shiftable parts, the gearing preferably being utilized to serve dual functions.

The foregoing and other objects and important features of the invention will become apparent to those skilled in the art as the disclosure is more fully made in the following detailed de-` scription and accompanying Sheets of drawings; in which:

Figure 1 is a longitudinal sectional view Y through a transmission embodying the invention, the view being illustrated with the reverse idler gearing shown as displaced from its actual position;

Figure 2 is a transverse sectional view taken along the line 2--2 of Figure 1, with portions of the gearing broken away to illustrate the invention more clearly; and

Figure 3 is a plan view on a reduced scale showing portions of the mainA driving gears.

As stated above, the transmission mechanism herein disclosed is preferably adapted for use as the change-speed gear of a vehicle; although, it will be understood that the principles ol' the invention may be similarly utilized in other instances. The disclosure is accordingly intended to be representative and not limiting.

As indicated in Figure 1, the reference character 'Ill designates generally a transmission housing. lAn upper portion of the transverse wall of the housingis'provided with antifrictlon bean ings II which journal a driving element orinput 5 shaft I2. This shaftmay be connected in A suitablemanner withan engine clutch, forfeitk ample,`not shown, of the type common'in' motor vehicles.

Rearwardly'of:thetbearings I the shaft I2 is-V and this enlargement is boredoutfto provides. cylindrical recess l6, .which carries any antiiriction bearing Il journaling a reduced end portieri I8 of a power output shaftA IS.` it `will be noted that the shafts I2,.andI 9.are rotatable inde-- pendently of each other andA are disposed coand formed as a driving bevel gear 2D. it will be rear end of the shaft Vis journaled in the rear wall i of the housing throughthe medium of means interposed between that shalt and a hollow coun- 40 tershaft 24. The rear end of the countershaft is journaled in a bearing 25 in the rear wall of the housing. 'I'he shaft22. extends Vthrough or is surrounded by the countershaft- 24, the rear portions of the two shafts being inter-journaled on a bearing or bushing 26.- The' front end ofthe shaft 22 has keyed thereon a driving element 21 including a central portion provided with a cylindrical recess 28 in which is carriedan antifriction `bearing 29. This bearing journals the forward end of the countershaft 24. The outer enlarged portion of the driving element, 21 is formed as a gear 30 which is preferably in constant mesh with the gear I5 on the driving shaft I2. From the description thus far it will be seen that the power output shaft 22 is 'continuously' driven as long as the driving shaft. I 2 is driven. The rear end of the. shaft 22 splined portion 3| which serves as means for 6o enabling the shaft to be connected to other drive any.

axially. The intermediatenpornon lofnneshait, I9 is splined-and the rear end thereoiisenlargedV understood that thegear 20 may be formed sepais provided with a Y asuste from the driving shaft optionally in either forward or reverse, shiftable drive means between the countershaft and output shaft, a second output shaft extending through the hollow countershaft, and means for driving the second output -between the countershaft and output shaft, a

second output shaft extending through the hollow countershaft, and means for driving the second output shaft from the driving element irrespective of rotation of or the direction of rotation of the countershaft.

3. Power transmission mechanism comprising a driving element having first and second gears; a coaxial output shaft; a parallel, hollow countershaft; drive means between the output shaft and countershaft; disconnectable drive means, including the rst gear oh the driving element, for driving the countershaft optionally in either forward or reverse; a second output shaft extending through the hollow countershaft; and means, including the second gear on the driving element, for driving the second output shaft independentll K of driving of the countershaft.

4. Power transmission mechanism comprising a driving element having first and second gears; a coaxial output shaft; a parallel, hollow countershaft; drive means between the output shaft and countershaft; a second output shaft extending through the hollow countershaft and including a drive member; means including said drive member and one of the gears on the aforesaid driving element for driving said second output shaft; and means shiftable in one position to be driven by said drive member to drive the countershaft in one direction and in another position to be. driven by the other of the gears on the aforesaid driving element to drive the countershaft in the other direction.

5. A change-speed transmission comprising a driving shaft, a second, coaxial shaft, a third,

hollow shaft spaced from the second shaft, shiftable change-speed gearing between the second and third shafts, disconnectible and reversible driving means between the driving shaft and the third shaft for rotating said third shaft in either forward or reverse, a fourth shaft extending through the hollow shaft, and means for driving said fourth shaft continuously from the driving shaft independently of the driving of the third shaft and irrespective of the direction of rotation thereof.

6. A change-speed transmission comprising a driving shaft having gear means thereon; a coaxial shaft journaled at one end in said driving shaft; a driven shaft spaced from said driving shaft and including a gear in driving engagement with the aforesaid gear means; a. second, hollow driven shaft surrounding the first driven shaft; shiftable gear means between the aforesaid coaxial shaft and the hollow shaft; idler gearing driven by the aforesaid gear means; and an element on the second driven shaft shiftable for optional driving engagement with the gear on the first driven shaft or the idler gearing.

'1. A change-speed transmission comprising a driving shaft having first and second gear means thereon: a coaxial shaft journaled at one end in said driving shaft; a driven. shaft spaced from said driving shaft and including a gear in driving engagement with the first of the aforesurr'ounding the first drivenshaft and having one end piloted in the gear on said first driven shaft; shiftable gear means between the aforesaid coaxial shaft and the hollow shaft; idler gearing driven by the second of the aforesaid gear means; and an element on the second driven shaft shiftable for optional driving engagement with the gear on the first driven shaft or the idler gearing.

8. A change-speed transmission comprising `a. driving shaft having first and second gears; a

coaxial output shaft having one end journaled" on said driving shaft; a hollow countershaft paralleling the output shaft; change-speed gearing between the output shaft and countershaft; a

second output shaft extending through the hollow countershaft; a drive element keyed on the second output shaft and including means journaling one end of the countershaft and first and second drive portions, the first meshing with the first gear on the driving shaft; idler gearing driven by the second gear on the driving shaft; and a shiftable gear element slidable on the countershaft into optional engagement with the idler gearing or with the second drive portion on the second output shaft.

9. Power transmission mechanism comprising a driving element having first and second gears; a parallel, hollow, driven shaft; a second driven shaft extending through the hollow shaft; means 4inter-journaling said driven shafts; a drive member keyed on one driven shaft and including first and second drive portions, the first of which meshes with the first gear on the driving element; idler gearing meshing withy the second gear on the driving element; and a shiftable gear element on the other driven shaft optionally slidable thereon intoy engagement with the idler gearing or the second drive portion on the aforesaid drive member.

10. Power transmission mechanism comprising a driving shaft having first and second gears; a parallel, hollow, driven shaft; a second driven shaft extending through the hollow shaft; means inter-journaling said driven shafts; a drive member keyed on the second driven shaft and including an internal drive portion and an external drive portion, the external drive portion meshing with the Vfirst gearl on the driving shaft; idler gearing meshing with the second gear on the driving shaft; and a shiftable double gear element on the other driven shaft optionally slidable thereon into engagement with the idler gearing or the internal drive portion on the aforesaid drive member.

11. A change-speed transmission comprising a driving shaft including a plurality of gear elements rotatable therewith; a second gear element, including a first drive part meshing with one of the driving-shaft gear elements, and a second drive part; a driven shaft journaled at one end on the second gear element; idler gearing including a gear meshing with another of the driving-shaft-gear elements; and a gear element on and rotatable with the driven shaft and shiftable thereon for optionalengagement with either the idler gearing or the second drive part of the second gear element.

RAYMOND R. ROHKAR.

said gear means; a second, hollow driven shaft 

